1. Field of Invention
This invention relates to a power amplifier module design using transistor, capacitor, matching network and package.
2. Description of Prior Art
A hybrid power amplifier typically includes a transistor, an input matching network and an output matching network. The input/output matching networks transform the input/output port impedance (typically 50 Ohm) to the optimum source/load impedance of the transistor to achieve the maximum output power. The matching networks typically need to have a characteristic impedance of a few Ohms to transform the port impedance to the optimum load impedance of a high power device. The input/output matching networks are typically printed on ceramic substrate such as Alumina (Al2O3). The bandwidth of the power amplifier is normally less than an octave since low impedance transmission lines are typically very wide and have large parasitic effect due to the dimensional mismatch with the small transistor die.